Holding the Dunkirk Perimeter

Since late May 1940, the British Expeditionary Force and part of the French army have been falling back toward Dunkirk, their last window on the sea. Operation Dynamo is in full swing: day and night, from the east mole to the beaches of Malo-les-Bains, destroyers, trawlers and small craft are lifting off tens of thousands of men under the bombs of the Luftwaffe. But this evacuation has a chance of succeeding only if someone, behind them, holds the enemy back long enough.

You are a British rearguard officer, deployed at Bergues, on the fortified line of the perimeter, along the canals that ring the pocket. Your men are exhausted, low on ammunition, harried by the German artillery tightening its grip. Ahead of you, the pressure mounts by the hour; behind you, the line of soldiers waiting to embark still stretches across the sand. Every hour gained on this front means one more ship putting to sea fully loaded.

You know what staying in position means: the line will hold, but those who hold it may have no boat left when they finally pull back. On 1 June 1940, amid the crash of shells, you must decide within a few hours.